Wishbone Flower Plant Profile

purple wishbone flowers (Torenia fournieri)

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Wishbone flowers (Torenia fournieri) are an excellent choice for bringing some color and life to a shadier part of the garden. Unlike many other flowers, these compact plants don't mind growing in a little shade. Their trumpet-shaped blooms come in several color choices; the primary species coloring is a dark blue-purple and lavender with yellow markings. Within each flower, a pair of stamens (the slender stalks) unites in a shape that resembles a wishbone, hence the plant’s common name.

Plant wishbone flowers in the spring after the threat of frost has passed. While they are annuals and will die once frost arrives in the fall, they grow quickly and bloom profusely from early summer all the way until when cold weather sets in. Moreover, the plants are deer-resistant and attractive to hummingbirds.

Botanical Name Torenia fournieri
Common Name Wishbone flower, bluewing
Plant Type Annual flower
Mature Size 6 to 18 inches tall (depending on the variety)
Sun Exposure Partial shade to full shade
Soil Type Loam, medium moisture, well-draining
Soil pH 6 to 6.5
Bloom Time June to frost
Flower Color Blue-purple, lavender, pink, rose, white
Hardiness Zones 2 to 11 (as an annual)
Native Area Asia

How to Grow Wishbone Flowers

If you want to grow your wishbone flowers from seed, start the seeds six to eight weeks before your area's projected last frost date. Note that the flowers don't transplant well, so the seeds should be started in peat or paper pots that you can plant along with the seedlings. In frost-free climates, wishbone flowers can be direct-seeded in your desired planting site outdoors about one week before your last expected frost date.

Don't cover the seeds with soil, as they need light to germinate. Keep the soil moist and relatively warm—around 70 degrees Fahrenheit—until the seeds germinate. After that, they can handle cooler temperatures. Pinching off the growing tip when it reaches a couple of inches high will help to create a bushier plant.

Aside from keeping your plants sufficiently watered and fed, there isn't much maintenance necessary. Deadheading (removing spent blooms) isn't essential, though it can help to encourage more growth and flowering. Furthermore, if the plant looks scraggly, you can clip it back to about half its height.

Light

Wishbone flowers are adaptable to many locations; however, the ideal spot gets morning sun and afternoon shade. If you live in a climate that has hot summers pick a fairly shady location for your plants.

Soil

These flowers prefer organically rich, loamy soil with a slightly acidic soil pH. Excellent soil drainage is essential to preventing root rot. To improve the soil quality, consider mixing in some compost at the time of planting.

Water

Wishbone flowers have moderate water needs. Water whenever the soil feels dry to the touch, but make sure your plants aren't sitting in soggy soil.

Temperature and Humidity

Wishbone flowers grow best in temperatures around 70 to 75 degrees Fahrenheit during the day and 65 to 70 degrees Fahrenheit at night. They can tolerate cooler temperatures, though frost will kill the plants. They also don’t like excessive heat or humidity and can benefit from a layer of mulch in hot climates to keep their roots cool.

Fertilizer

To keep wishbone flowers healthy and blooming, provide a balanced, all-purpose fertilizer roughly every few weeks throughout the growing season (spring to fall). You can either use a liquid fertilizer or a slow-release granule fertilizer, following package instructions.

Propagating Wishbone Flowers

To propagate wishbone flowers, take stem cuttings that are at least 6 inches long from an existing plant. Try to get a node (raised bump) at the bottom of the stem, which is likely to root. Remove any leaves on the lower half of the cutting, and place it in water. Once roots begin to grow, plant the cutting in a paper or peat pot filled with a quality potting mix, and keep the soil moist. Then, bring the plant outside for increasingly longer stretches for about a week to get it used to being outdoors before planting it in your garden.

Common Pests and Diseases

Wishbone flowers don't have any major problems with pests or diseases. But they can be susceptible to fungal diseases, such as powdery mildew, that can discolor and damage their leaves and stems. Providing optimal growing conditions and good air circulation for the plants should help to prevent most problems.

Moreover, some common garden pests, including aphids and whiteflies, will prey on wishbone flowers. With aphids, you might notice a sticky residue that these insects leave behind as they feed on the plants. And with whiteflies, you often can see the tiny flying insects rise up in a cloud when the plant is disturbed. You can control these problems with insecticidal soap.

Varieties of Wishbone Flowers

There are several varieties of wishbone flowers that range in appearance, including:

  • 'Catalina White Linen': This plant sports pure white flowers and reaches about 16 inches tall. 
  • 'Kauai Rose': This variety has bright pink and white blooms and is notable for its heat and humidity tolerance.
  • 'Moon Purple': This variety features lavender and dark purple blooms and grows to about 10 inches tall.